Whether ablation therapy for atrial fibrillation (AF) reduces stroke risk has long been the subject of controversy. The Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM) trial randomized patients to rate control vs rhythm control of AF and found a higher number of strokes in the rhythm control group, which was a seemingly paradoxical finding that was due to discontinuation of warfarin in patients apparently in sinus rhythm while taking antiarrhythmic drugs. It later became recognized that most patients with AF, even if in sinus rhythm (assessed by electrocardiographic [ECG] monitoring at office visit), continue to have asymptomatic AF episodes that can lead to embolic events.